Manufacture of cement mixtures



106. COMPOSITIONS, f T l 3] COATING R PLASTIC. i i

Patented Feb. 6, 1923. 1,444,309

UNITED STATES PATENT OFFICE.

FABIO FERRARI, or ROME, ITALY, ASSIGNOR 'ro THE COMPANY, BOMBRINI PARODI- DELFINO, or noun, ITALY.

MANUFACTURE OF CEMENT MIXTURES.

No Drawing. Application filed August 23, 1920. Serial No. 405,417.

To all whomz'tmay concern: disintegrating action of sea water or sul- Be it known that I, FABIO FERRARI, a sub phate water owing to the presence of comject of the King of Italy, and residing at pounds of aluminate of calcium in the Port- Rome, Italy, whose post address is Piazza S. land cement; these aluminates uniting with 55 5 S. Apostoli No. 18, have invented certain the sulphates of the water in contact with new and useful Improved Manufacture of the cement form disintegrating difi'usive Cement Mixtures, of which the following is chemical combinations. To eliminate this a specification. drawback according to the present inven- This invention relates to a binding or cetion a new mixture is proposed in which in- 60 ment mixture for the preparation of agstead of Portland cement, a special cem n glomer'ates resisting the act1on of sea water containin Fe O and Al O in the ro oror of sulphated water, characterized by a Parnendteni'ent %h1s reduction to a fine powder of a cement fre pnportfon is about 0.5) absolutely rfree from binary calcium compgundlsjm lirom alummate compgungls. 65

or iron and ht a ozzuolana sgbstamcal- By means of th e cement of the above culated on the basis of lts ab sorbing power mentioned type, investigated by the a pliand of the lime which the cement can give cant, and of a Fozzuolanic substangg 2ozas1c s a off by hydration of its components, and of zuolana ro er s ea m trass the sand with which it has to be subseetc. reduced to the normal degrees of find-'70 quently mixed in order to be used in sea ness or ordinary cements, a cement .mix-

' water or in surrounding places where sulture is prepared which, on being mixed with phates abound. sillcious sand gives agglomerates resisting After numerous experiments, the appli- 1n an absolute manner the action of sea cant has come to the conclusion that all Water or of sulphated water generally, and 75 strongly basic cement-containing mortars, absolutely impermeable.

when they are entirely or partly submerged, The proportions of the two ingredients deteriorate in the course of time owing to of the said cement mixture, are calculated the diffusion of the lime liberated by the on the basis of the determination; carried hydration of the cements themselves. Alout in accordance with the ordinary meth- 80 though mortars containing Aegir cement 0dS (V1cat, Mayer, etc.), of the percentages (free from alumina) oraspecial cement such f lune hat the cement can give off by hvas that which forms the subject matter of my dIatIOII- n 0f the llme Wh1ch can be ab- Patent No. 1,372,315 (in which the sesquisorbed by contact respectively by the pozoxides are converted into ternary silicates o anic su stance above referred to, and by 85 that are .not attach d ,b water nd b the SlllCOllS sand with which the said mixsaline solutions) are, in surroundings which tule h s to be Subsequently used. abound in sulphates, absolutely stable as or the above calculation also the sand regards the action of these salts, they are has been dered whlch 1s but an 1nnot quite free from the drawbacks due to gredlent f he conglomerate when 1t 1s em- 90 the action of the phenomenon indicated. p y the'sand bg accordlng 170 Its P It is known that the lime contained in l y III Ie 01' less like pozzuolana. Portland cement is completely chemically sugp smgthen: 4 combined to form insoluble compounds, by ll a0 WhlCh can be given off by hydrathe addition of substances with strong poz- 1 n f 10 parts by weight of the speclal 95 zuolanic action. cement This joint use of the two materials, ,ce-

C30 which C b fixed by 1 parts by Win16. pozzuolana was long: ago tried bf' gh f pp zuolamc substance.

. Micha'ells but the practical results have 0 0&0 Whlch can be fixed y 100 P y not till now answered the previous expecght of silicious sand. 100

tations of the author. As it was ascertained the said mixtures do not resist the r proportlqn according to whlch W111 used for the preparation of the conglomerates the mixture special cement-pozzuolana and silicious san The percentage of special cement (m) and of pozzuolanic substance (3 in the mixtures to 'be prepared will be:

100 (aor) a+b The mixture described is obviously capable of general application: its use in sea work or works intended to remain in continuous contact with water rich in sulphates (and more particularly in movable works such as floating docks, keels of ships, etc.) is more particularly owing to the special characteristic features mentioned in the foregoing.

Having now particularly described and water or to water rich of sulphates.

In testimony whereof I have hereunto signed my name in the presence of two witnesses.

v FABIO FERRARI. Witnesses:

GINA CRINPANELLI, DUOLIO NARDENI. 

